How We See the Invisible World: Microscopy

These flashcards cover key concepts related to microscopy and the properties of light as discussed in the lecture.

Microscopy

A technique used to visualize small objects, typically using a microscope.

Brightfield Microscopy

A microscopy technique that renders a darker image on a lighter background.

Darkfield Microscopy

A microscopy technique that increases contrast by producing a brighter image on a darker background.

Wavelength

The distance between one peak of a wave and the next peak.

Amplitude

The height of a wave.

Frequency

The rate of oscillation of a wave.

Reflection

When a wave bounces off of a material.

Absorbance

Occurs when a material captures the energy of a light wave.

Transmittance

Occurs when light travels through a material.

Refraction

The change of speed and direction of light waves as they pass from one medium to another.

Resolving Power

The ability to distinguish two adjacent objects or points from one another.

Numerical Aperture

A description of the relative efficiency of a lens in gathering light rays.

Oil Immersion Lens

A type of lens used to improve resolution by reducing light refraction.

Phase-Contrast Microscope

A microscope that uses phase differences between light rays to create contrast in images.

Transmission Electron Microscope (TEM)

An electron microscope that transmits electron beams through a specimen to examine internal structures.

Scanning Electron Microscope (SEM)

An electron microscope that scans the surface of a specimen to create a three-dimensional image.

Staining

The process of applying color to a specimen to enhance visibility under a microscope.

Gram Staining

A differential staining technique used to distinguish between gram-positive and gram-negative bacteria.

Basic Dye

A positively charged dye that binds to negatively charged molecules in cells.

Negative Staining

A staining method that does not adhere to the specimen but instead settles around it, creating a silhouette.

Capsule Staining

A staining technique used to visualize the capsule surrounding certain bacteria.